package com.hmall.service.impl;

import com.alibaba.fastjson.JSON;
import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
import com.hmall.common.client.ItemClient;
import com.hmall.common.dto.PageDTO;
import com.hmall.common.pojo.Item;
import com.hmall.doc.ItemDoc;
import com.hmall.dto.RequestParams;
import com.hmall.service.SearchService;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.functionscore.FunctionScoreQueryBuilder;
import org.elasticsearch.index.query.functionscore.ScoreFunctionBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortOrder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.io.IOException;
import java.util.*;

@Service
public class SearchServiceImpl implements SearchService {

    @Autowired
    private RestHighLevelClient client;

    @Override
    public List<String> suggestion(String key) {

        try {
            // 1.准备Request
            SearchRequest request = new SearchRequest("item");
            // 2.准备DSL
            request.source().suggest(new SuggestBuilder().addSuggestion(
                    "suggestions",
                    SuggestBuilders.completionSuggestion("suggestion")
                            .prefix(key)
                            .skipDuplicates(true)
                            .size(10)
            ));
            // 3.发起请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            // 4.解析结果
            Suggest suggest = response.getSuggest();
            // 4.1.根据补全查询名称，获取补全结果
            CompletionSuggestion suggestions = suggest.getSuggestion("suggestions");
            // 4.2.获取options
            List<CompletionSuggestion.Entry.Option> options = suggestions.getOptions();
            // 4.3.遍历
            List<String> list = new ArrayList<>(options.size());
            for (CompletionSuggestion.Entry.Option option : options) {
                String text = option.getText().toString();
                list.add(text);
            }
            return list;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public Map<String, List<String>> getfilter(RequestParams requestParams) {

        try {
            SearchRequest request = new SearchRequest("item");
            //query
            buildBasicQuery(requestParams, request);
            //设置size
            request.source().size(0);
            //聚合
            buildAggregation(request);
            //发出请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            //解析结果
            Map<String, List<String>> result = new HashMap<>();
            Aggregations aggregations = response.getAggregations();
            //根据品牌名称，获得品牌结果
            List<String> categoryList = getAggByName(aggregations, "categoryAgg");
            result.put("category", categoryList);
            List<String> brandList = getAggByName(aggregations, "brandAgg");
            result.put("brand", brandList);
            return result;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }


    }

    private void buildBasicQuery(RequestParams requestParams, SearchRequest request) {
        //构建booleanQuery
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        //关键字搜索
        String key = requestParams.getKey();
        if (key == null || "".equals(key)) {
            boolQuery.must(QueryBuilders.matchAllQuery());
        } else {
            boolQuery.must(QueryBuilders.matchQuery("all", key));
        }
        //品牌条件
        if (requestParams.getBrand() != null && !requestParams.getBrand().equals("")) {
            boolQuery.filter(QueryBuilders.termQuery("brand", requestParams.getBrand()));
        }
        //分类条件
        if (requestParams.getCategory() != null && requestParams.getCategory().equals("")) {
            boolQuery.filter(QueryBuilders.termQuery("category", requestParams.getCategory()));
        }
        if (requestParams.getMinPrice() != null && requestParams.getMaxPrice() != null) {
            boolQuery.filter(QueryBuilders.rangeQuery("price").gte(requestParams.getMinPrice()).lte(requestParams.getMaxPrice()));
        }
        request.source().query(boolQuery);
    }

    private void buildAggregation(SearchRequest request) {
        request.source().aggregation(AggregationBuilders.terms("brandAgg").field("brand").size(20));
        request.source().aggregation(AggregationBuilders.terms("categoryAgg").field("category").size(20));
    }

    private List<String> getAggByName(Aggregations aggregations, String aggName) {
        //根据聚合名称获得聚合结果
        Terms brandTerms = aggregations.get(aggName);
        //获取buckets
        List<? extends Terms.Bucket> buckets = brandTerms.getBuckets();
        //遍历
        List<String> brandList = new ArrayList<>();
        for (Terms.Bucket bucket : buckets) {
            String string = bucket.getKeyAsString();
            brandList.add(string);
        }
        return brandList;
    }

    //--------------------------------------------------

    /**
     * 搜索
     *
     * @param requestParams
     * @return
     */
    @Override
    public PageDTO<ItemDoc> list(RequestParams requestParams) {
        try {
            SearchRequest request = new SearchRequest("item");

            //构建booleanQuery
            BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
            //关键字搜索
            String key = requestParams.getKey();
            if (key == null || "".equals(key)) {
                boolQuery.must(QueryBuilders.matchAllQuery());
            } else {
                boolQuery.must(QueryBuilders.matchQuery("all", key));
            }

            //品牌条件
            if (requestParams.getBrand() != null && !requestParams.getBrand().equals("")) {
                boolQuery.filter(QueryBuilders.termQuery("brand", requestParams.getBrand()));
            }
            //分类条件
            if (requestParams.getCategory() != null && !requestParams.getCategory().equals("")) {
                boolQuery.filter(QueryBuilders.termQuery("category", requestParams.getCategory()));
            }
            if (requestParams.getMinPrice() != null && requestParams.getMaxPrice() != null) {
                boolQuery.filter(QueryBuilders.rangeQuery("price").gte(requestParams.getMinPrice()*100).lte(requestParams.getMaxPrice()*100));
            }

            request.source().query(boolQuery);

            //排序
            String sort = requestParams.getSortBy();
            if (sort.equals("price")){
                request.source().sort("price", SortOrder.ASC);
            }else if (sort.equals("sold")){
                request.source().sort("price", SortOrder.DESC);
            }

            // 2.2.分页
            int page = requestParams.getPage();
            int size = requestParams.getSize();
            request.source().from((page - 1) * size).size(size);

            //高亮
            request.source().highlighter(new HighlightBuilder()
                    .field("name")
                    .requireFieldMatch(false));

             //2.算分控制
            FunctionScoreQueryBuilder functionScoreQuery =
                    QueryBuilders.functionScoreQuery(
                            // 原始查询，相关性算分的查询
                            boolQuery,
                            // function score的数组
                            new FunctionScoreQueryBuilder.FilterFunctionBuilder[]{
                                    // 其中的一个function score 元素
                                    new FunctionScoreQueryBuilder.FilterFunctionBuilder(
                                            // 过滤条件
                                            QueryBuilders.termQuery("isAD", true),
                                            // 算分函数
                                            ScoreFunctionBuilders.weightFactorFunction(100)
                                    )
                            });
            request.source().query(functionScoreQuery);

            // 3.发送请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            // 4.解析响应
            return handleResponse(response);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }




    // 结果解析
    private PageDTO<ItemDoc> handleResponse(SearchResponse response) {

        // 4.解析响应
        SearchHits searchHits = response.getHits();
        // 4.1.获取总条数
        long total = searchHits.getTotalHits().value;
        // 4.2.文档数组
        SearchHit[] hits = searchHits.getHits();
        // 4.3.遍历
        List<ItemDoc> itemDocs = new ArrayList<>();
        for (SearchHit hit : hits) {
            // 获取文档source
            String json = hit.getSourceAsString();
            // 反序列化
            ItemDoc itemDoc = JSON.parseObject(json, ItemDoc.class);
            // 获取高亮结果
            Map<String, HighlightField> highlightFields = hit.getHighlightFields();
            if (!CollectionUtils.isEmpty(highlightFields)) {
                // 根据字段名获取高亮结果
                HighlightField highlightField = highlightFields.get("name");
                if (highlightField != null) {
                    // 获取高亮值
                    String name = highlightField.getFragments()[0].string();
                    // 覆盖非高亮结果
                    itemDoc.setName(name);
                }
            }
            // 放入集合
            itemDocs.add(itemDoc);
        }
        // 4.4.封装返回
        return new PageDTO<ItemDoc>(total, itemDocs);
    }


    //--------------------阿珍--------------

    @Autowired
    private ItemClient itemClient;

    @Override
    public void deleteById(Long id) {
        try {
            // 1.准备Request
            DeleteRequest request = new DeleteRequest("item", id.toString());
            // 2.发送请求
            client.delete(request, RequestOptions.DEFAULT);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    public void insertById(Long id) {
        try {
            // 0.根据id查询酒店数据
            Item item = itemClient.getById(id);
            // 转换为文档类型
            ItemDoc itemDoc = new ItemDoc(item);
            // 1.准备Request对象
            IndexRequest request = new IndexRequest("item").id(item.getId().toString());
            // 2.准备Json文档
            request.source(JSON.toJSONString(itemDoc), XContentType.JSON);
            // 3.发送请求
            client.index(request, RequestOptions.DEFAULT);
            client.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

}

